Soap-Making Manual / A Practical Handbook on the Raw Materials, Their Manipulation, Analysis and Control in the Modern Soap Plant.

by Edgar George Thomssen

CHAPTER I. Page.
Raw Materials Used in Soap Making [1-30]
1. Soap Defined [1]
2. Oils and Fats [1-2]
3. Saponification Defined [2-3]
4. Fats and Oils Used in Soap Manufacture [3-4]
Fullers' Earth Process for Bleaching Tallow [4-6]
Method for Further Improvement of Color in Tallow [6]
Vegetable Oils [6-9]
Chrome Bleaching of Palm Oil [9-12]
Air Bleaching of Palm Oil [12-16]
5. Rancidity of Oils and Fats [16-18]
Prevention of Rancidity [18]
6. Chemical Constants of Oils and Fats [18-19]
7. Oil Hardening or Hydrogenating [19-21]
8. Grease [21-22]
9. Rosin (Colophony, Yellow Rosin, Resina) [22-23]
10. Rosin Saponification [23-24]
11. Naphthenic Acids [24-25]
12. Alkalis [25-26]
Caustic Soda [26]
Caustic Potash [26-28]
Sodium Carbonate (Soda Ash) [28-29]
Potassium Carbonate [29]
13. Additional Material Used in Soap Making [29-30]
CHAPTER II.
Construction and Equipment of a Soap Plant [31-34]
CHAPTER III.
Classification of Soap Making Methods [35-46]
1. Full Boiled Soaps [36-42]
2. Cold Process [43-44]
3. Carbonate Saponification [45-46]
CHAPTER IV.
Classification of Soaps [47-104]
1. Laundry Soap [48]
Semi-Boiled Laundry Soap [49-50]
Settled Rosin Soap [50-54]
2. Chip Soap [54-55]
Cold Made Chip Soap [55-56]
Unfilled Chip Soap [56]
3. Soap Powders [56-59]
Light Powders [60-61]
4. Scouring Powders [61]
5. Scouring Soap [61-62]
6. Floating Soap [62-65]
7. Toilet Soap [65-68]
Cheaper Toilet Soaps [68-69]
Run and Glued-up Soaps [69-71]
Curd Soap [71-72]
Cold Made Toilet Soaps [72-73]
Perfuming and Coloring Toilet Soaps [73-75]
Coloring Soap [75-76]
8. Medicinal Soaps [76-77]
Sulphur Soaps [77]
Tar Soap [77]
Soaps Containing Phenols [77-78]
Peroxide Soap [78]
Mercury Soaps [78]
Less Important Medicinal Soaps [78-79]
9. Castile Soap [79-81]
10. Eschweger Soap [81-82]
11. Transparent Soap [82-84]
Cold Made Transparent Soap [84-87]
12. Shaving Soaps [87-90]
Shaving Powder [90]
Shaving Cream [90-93]
13. Pumice or Sand Soaps [93-94]
14. Liquid Soaps [94-95]
15. Use of Hardened Oils in Toilet Soaps [96-98]
16. Textile Soaps [98]
Scouring and Fulling Soaps for Wool [98-100]
Wool Thrower's Soap [100-101]
Worsted Finishing Soaps [101]
Soaps Used in the Silk Industry [101-103]
Soaps Used for Cotton Goods [103-104]
17. Sulphonated Oils [104-105]
CHAPTER V.
Glycerine Recovery [105-126]
1. Methods of Saponification [105-106]
Recovery of Glycerine from Spent Lye [106-113]
Twitchell Process [113-118]
Autoclave Saponification [118]
Lime Saponification [118-120]
Acid Saponification [120-121]
Aqueous Saponification [121]
Splitting Fats with Ferments [121-123]
Krebitz Process [123-125]
2. Distillation of Fatty Acids [125-126]
CHAPTER VI.
Analytical Methods [127-164]
1. Analysis of Oils and Fats [128]
Free Fatty Acids [128-130]
Moisture [130]
Titer [130-132]
Determination of Unsaponifiable Matter [132-133]
Test for Color of Soap [133-134]
Testing of Alkalis Used in Soap Making [134-137]
2. Soap Analysis [137-138]
Moisture [138-139]
Free Alkali or Acid [139-142]
Insoluble Matter [143]
Starch and Gelatine [143-144]
Total Fatty and Resin Acids [144]
Determination of Rosin [144-147]
Total Alkali [147-148]
Unsaponifiable Matter [148]
Silica and Silicates [148-149]
Glycerine in Soap [149-150]
Sugar in Soap [150]
3. Glycerine Analysis [150-151]
Sampling [151]
Analysis [151-154]
Acetin Process for the Determination of Glycerol [155-156]
The Method [156-159]
Ways of Calculating Actual Glycerol Contents [159-160]
Bichromate Process for Glycerol Determination
Reagents Required [160-161]
The Method [161-162]
Sampling Crude Glycerine [162-164]
CHAPTER VII
Standard Methods for the Sampling and Analysis of Commercial Fats and Oils [165-195]
1. Scope, Applicability and Limitations of the Methods [165-166]
Scope [165]
Applicability [166]
Limitations [166]
Sampling [166-169]
Tank Cars [166-167]
Barrels, Tierces, Casks, Drums, and Other Packages [168]
2. Analysis [169-183]
Sample [169]
Moisture and Volatile Matter [170-172]
Insoluble Impurities [172-173]
Soluble Mineral Matter [173]
Free Fatty Acids [174]
Titer [174-175]
Unsaponifiable Matter [176-177]
Iodine Number-Wijs Method [177-181]
Saponification Number (Koettstorfer Number) [181]
Melting Point [181-182]
Cloud Test [182-184]
3. Notes of the Above Methods [184-196]
Sampling [183]
Moisture and Volatile Matter [184-187]
Insoluble Impurities [187]
Soluble Mineral Matter [187-188]
Free Fatty Acid [188-189]
Titer [189]
Unsaponified Matter [190-193]
Melting Point [193-196]
Plant and Machinery [198-219]
Illustrations of Machinery and Layouts of the Plant of a Modern Soap Making Establishment [198-219]
Appendix [219-237]
Useful Tables
Index [239]

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CHAPTER I

Raw Materials Used in Soap Making.

Soap is ordinarily thought of as the common cleansing agent well known to everyone. In a general and strictly chemical sense this term is applied to the salts of the non-volatile fatty acids. These salts are not only those formed by the alkali metals, sodium and potassium, but also those formed by the heavy metals and alkaline earths. Thus we have the insoluble soaps of lime and magnesia formed when we attempt to wash in "hard water"; again aluminum soaps are used extensively in polishing materials and to thicken lubricating oils; ammonia or "benzine" soaps are employed among the dry cleaners. Commonly, however, when we speak of soap we limit it to the sodium or potassium salt of a higher fatty acid.

It is very generally known that soap is made by combining a fat or oil with a water solution of sodium hydroxide (caustic soda lye), or potassium hydroxide (caustic potash). Sodium soaps are always harder than potassium soaps, provided the same fat or oil is used in both cases.

The detergent properties of soap are due to the fact that it acts as an alkali regulator, that is, when water comes into contact with soap, it undergoes what is called hydrolytic dissociation. This means that it is broken down by water into other substances. Just what these substances are is subject to controversy, though it is presumed caustic alkali and the acid alkali salt of the fatty acids are formed.

OILS AND FATS.

There is no sharp distinction between fat and oil. By "oil" the layman has the impression of a liquid which at warm temperature will flow as a slippery, lubricating, viscous fluid; by "fat" he understands a greasy, solid substance unctuous to the touch. It thus becomes necessary to differentiate the oils and fats used in the manufacture of soap.